21394550 has 24 divisors (see below), whose sum is σ = 39934200. Its totient is φ = 8527680.

The previous prime is 21394519. The next prime is 21394561. The reversal of 21394550 is 5549312.

It is a zygodrome in base 9.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18386 + ... + 19514.

It is an arithmetic number, because the mean of its divisors is an integer number (1663925).

Almost surely, 2^21394550 is an apocalyptic number.

21394550 is a deficient number, since it is larger than the sum of its proper divisors (18539650).

21394550 is a wasteful number, since it uses less digits than its factorization.

21394550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520 (or 1515 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 21394550 is about 4625.4243048611. The cubic root of 21394550 is about 277.6095393107.

The spelling of 21394550 in words is "twenty-one million, three hundred ninety-four thousand, five hundred fifty".